There are millions of reasons to think Congress won't do much about global warming, all stockpiled in the lobbying budgets of the U.S.'s mightiest interest groups--automakers and other manufacturers, environmentalists, labor unions, farmers, oil companies, coal companies, utilities, the military, antitaxers and so on. A Washington axiom holds that it's always easier to do nothing than to do something. By that standard, tackling climate change, which would affect every industry and every private life, looks almost impossible.

On the other hand, there's John Dingell. Michigan's eternal Congressman, defender of Detroit's carbon-spewing gas hogs, would seem an unlikely cause for optimism. After all, his...